Transcript Energy in Ecosystems

Energy in
Ecosystems
Food Web:
• a group of food chains
showing all of the
feeding relationships
in an ecosystem.
All Food
Webs:
• Trophic
level
—a
• Original
Energy
(SUN)
layer
in the
feeding
• Producers of an
relationship
• Consumers one link in
ecosystem,
the• Decomposers
food chain/web.
• Soil
• Biomass
— total
• Arrows showing energy
amount
of organic
flow!
material present in a
trophic level.
So, all producers are
at the same trophic
level and all primary
consumers are at the
next trophic level.
Organic = is
currently living or
lived in the past
Energy/Ecological Pyramids
http://www.vtaide.com/png/foodchains.htm
http://www.earthforce.org/files/1284_image2_Energy_Pyramid_for_
Galvbay.jpg
• Another way to look at
trophic levels.
• a diagram showing the
relative amounts of
energy/biomass in the
different trophic levels.
• Lowest trophic levels
are at the bottom:
Producers have the
greatest biomass.
Example of an Energy Pyramid
1 MAN
MAN
0.1%
10%
100 %
of the
sun’s
energy
FOX
1%
10%
10%
RABBIT
Rabbit
90%
Energy Lost
during
conversion
to heat,
waste….
90%
10%
Grass
90%
10 FOXES
100
RABBITS
1000
Bunches of
GRASS
- The decreasing size of the pyramid shows
that each level of the pyramid has a smaller
and smaller number of those organisms.
Population:
How many of a
specific species
can live in an
area?
Carrying Capacity:
• The maximum population a
community can tolerate for
extended periods of time.
Usually determined by
abiotic factors …
Community =
the plants and
animals found
in an area
Abiotic Factors =
non-living
characteristics of the
environment.
For example:
An extended period
of time … the
environment remains
healthy and future
generations of organisms
are able to continue to live
within the community
-Sunlight
-Moisture
-Space
-Pollution
-Landscape/Terrain
Limiting Factors:
• Anything that keeps a population from
over-growing the resources available.
• Consider how changing the factors that affect
carrying capacity can alter the population size
of a species.
Predation
Disease
Floods
Accidents
Drought
Fire
Hunting
Pollution
Shade
Parasites
Storms
Starvation
Habitat Loss